The rotating parallel-plate viscometer

In a parallel-plate geometry, the upper plate is usually rotated and the couple C is Uke-wise measured on the upper plate. The shear rate varies from zero at the centre to aw/h at the edge of the plates, where a is the plate radius, h the gap and co the rotation rate in rad/ s. The shear rate at the edge is given by 

Tube or pipe viscometers take many forms, but they should all be able to give the pressure-drop P as a function of flow rate Q for situations where the tube is long enough to be able to neglect entrance and end effects, say L/a 50. In this case we can calculate the viscosity as a function of the wall shear rate, y, which is given by 

What do you expect to find in a good rheology laboratory The answer depends very much on the particular field of interest. Here we shall discuss what we would anticipate for a number of industrial situations, but the same would be true for academic studies in the same general area  

Personal products and cosmetics creams, lotions, pastes  

This is not an exhaustive list (for which see Whorlow s book [1]), but liquids foxmd in any other areas fall somewhere within those examples found in this list. 

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